group name completion problem on secondary servers

[Sébastien Kirche]

Hi,

when I first came on using Gnus, I defined my ISP news server as the
gnus-select-method and subscribed to some groups.

I later subscribed to the same groups via another server directly from
the *Server* buffer and keep for a moment my ISP server.

Because sometimes my ISP news server is down and that is making Gnus
hang during startup (and also because I remember to have read some
advices about it), few days ago I decided to rid the primary server to
set the gnus-select-method to (nnnil "") and purge the old subscribed
groups.

Now when I want to complete a group name for a cross-post or
followup-to, I cannot simply write the group name anymore but I have to
prefix the name with the method.
E.g. : nntp+news.cuq.org:fr.comp.applications.emacs instead of the
shorter fr.comp.applications.emacs.

I suppose that during the time that the group was also subscribed via
the gnus-select-method the completion was implicitly upon it. 

How could I make Gnus complete the group names regarding those I am
actually subscribed to, or those available via the servers listed in the
*Server* buffer ?

Thanks for help.
-- 
Sébastien Kirche